Knee structure for artifical leg



March 3, 1959 uzEY 2,875,448

KNEE STRUCTURE FOR ARTIFICIAL LEG Filed July 16,1957

3 Sheets-Sheet l INVENTOR ATTORNEYS March 3, 1

GIGUZEY KNEE STRUCTURE FOR ARTIFICIAL LEG Filed July 16, 1957 ilg nl NIf 5 Sheets-s 7d ENTOR,

ATTORNEY March 3, 1959 e. GUZEY 7 2, 7 48 KNEE STRUCTURE FOR ARTIFICIALLEG Filed July 16, 1957 3 Sheets-Sheet 3 ATTORNEYS United States Patent2,875,448 KNEE STRUCTURE FOR ARTIFICIAL LEG Application July 16, 1957,Serial No. 672,145

4 Claims. (Cl. 3-28) The present invention relates to knee structures,for artificial legs, and more particularly to such structures whichclosely simulates the movement of a natural knee.

The primary object of the invention is to provide a knee structure forartificial legs which maintains a rela-. tively even tension on thejoint throughout the bending movement thereof.

Another object of the invention is to provide a knee structure forartificial legs in. which the tension applied to the joint can bequickly and easily adjusted to accommodate the movement of the user.

A further object of the invention is to provide a knee structure forartificial limbs which is extremely light in weight and which can beadded to an artificial limb without increasing the weight thereof.

A still further object of the invention is to provide a knee structureof the character described above which is inexpensive to manufacture,simple to use, and which can be adjusted with a minimum of training andequip ment.

Other objects and advantages will become apparent in the followingspecification when considered in the light of the attached drawings, inwhich:

Figure 1. is a fragmentary side elevation of the invention.

Figure 2 is an enlarged fragmentary vertical crosssection taken throughthe knee joint from front to rear. Figure 3 is a fragmentary verticalcross-section taken along the line 3-3 of Figure 2, looking in thedirection of the arrows.

Figure 4is a semi-diagrammatic view illustrating the knee joint in erectposition. I

Figure 5 is a view similarto Figure 4 illustrating the knee joint in apartially bent position.

Figure 6 is a perspective view of the band support bracket removed fromthe leg.

Figure 7 is an enlarged fragmentary horizontal cross section taken alongthe line 77 of Figure 2,'looking in the direction ofthe arrows.

Figure 8 is a side elevation shown partly broken away and in section ofa modified form of knee joint.

Figure 9 is a fragmentary enlarged front elevation of a detail of thestructure illustrated in Figure 8.

Figure 10 is an enlarged fragmentary vertical cross-' section takenalong the line 10 10 of Figure 8, looking in the direction of thearrows. 1

Referring now to the drawings in detail wherein like referencecharacters indicate like parts throughout the several figures, thereference numeral indicates generally a knee joint structure of anartificial leg.

. The knee structure 20 is connected between a hollow lower leg member21 and a hollow upper leg member 22. The lower leg member 21 has itsupper end C011. nected to the lower end of the upper leg member 22 by i24 are of conventional design and provide a pivotal knee means of a pairof pivot members 23, 24 arranged in axially aligned horizontal relationon opposite sides of the upper and lowerv leg members 22, 21,respectively.

, Theleg members 21, 22 and their pivot connections 23,

action for the user.

A mounting bar 25 is positioned within the hollow lower leg member 21and is horizontally arranged extending from front to rear thereof, asshown in Figure 2. The mounting member 25 has depending flanges 26, 27on its opposite ends which are secured to the lower leg member 21 bysecuring elements 28.

. A resilient headed bushing 29 extends upwardly through the forward endof the mounting bar 25 and has amounting bolt 30 extending therethroughfor vertical sliding movement. A nut 31 is threaded onto the lower endof the mounting bolt 30 and engages against the head 29a of the headedbushing 29. The mounting bolt-30 is forwardly offset at 32 and issupported for sliding movement in an upright position by a bracket 33secured to the lower leg member 21 by securing element.34.,

A resilient bushing 35 encompasses the bolt '30 and spaces the bracket33'therefrom. A head member 36 is threadedlyengaged over the upper endof the bolt 30 and is locked in position thereon by a lock nut 37. Acushion 38 is secured to the upper end of the head member 36 by means ofsecuring elements 39.

An angular bracket 40 is mounted on the lower end of the upper legmember 22 by means of securing elements 41 and has a cushion 42 securedto its lower face by means of securing elements 43. Thecushions 38 and42 are vertically aligned, engage together to move the mounting bolt 30downwardly and to brace the lower leg member 21 and the upper leg member22 in straight position. v

The head 36 serves as a limit for the pivotal movementof the lower legmember 21 with respect to the upper leg member 22 and can be verticallyadjusted on theupper end of the mounting bolt 30 as required.

A coil spring 44 has its lower end engaged against the mounting bar 25encompassing the headed bushing 29 and has its upper end engaged againsta spring saddle 45 through which the mounting bolt 30 extends. Anelongated arm 46, as shown in Figure 7', 'is provided with a bore 47adjacent one end thereof through which the mounting bolt30 extends.

The elongated arm 46 is engaged against the spring saddle 45 and securedthereagainst by a lock nut 48. The elongated arm 46 is provided withupstanding cars 49 on opposite sides thereof which engage the nut 48 andrestrain it against rotation with respect to the arm 46.

The mounting bolt 30 is resiliently supported by the spring 44. Thespring 44 is relatively stiff and assists in absorbing the shock ofbending the knee and walking.

A generally rectangular bar 50 is arranged in .vertically spacedrelation above the arm 46 and has a pair of elongated bolts 51 extendingdownwardly therethrough.

and through'the arm 46. The bolts 51 are. arranged in spaced parallelrelation and have elongated sleeve type nuts 52 threadedly engagedthereon. The nuts 52 extend through the arm 46 to through.

The nuts 52 each are provided with flanges 53 at their removed from themounting bolt 30. Mounting hope 56 are pivotally secured to oppositeends of the bar 50, for reasons to be assigned.

A transverse support 57 is provided with depending end portions 58 andis secured in transverse horizontal position within the upper leg member22 spaced sub stantially above the pivots 23, 24. The support 57 isguide the bolts 51 there-' enemas detachably secured to the upper legmember 22 by means of securing elements 59.

An arcuate support member 60 is positioned centrally on the support 57and extends perpendicularly thereto. The support 57 is welded to thebracket 60 intermediate the opposite ends thereof. Aligned cars 61, 62extend upwardly from the side edges of the bracket 60 adjacent theopposite ends thereof and have a roller 63 journalled therein at eachend of the bracket 60.

. The rollers 63 are positioned on the upper side of the bracket 60 ascan be best seen in Figure 6. A band of friction material 64 is securedto the bracket 60 between the rollers 63 by any suitable means such asadhesives, rivets, or the like.

A steel band 65 is threaded through the loops 56 and securedto itself asat 66 toattach the steel band to the loops S6. The opposite end of thesteel band 65 has an upstanding flange 67 formed thereon.

A second steel band 68 has one end thereof threaded through the loop 56opposite the band 65 and secured to itself at 69 to connect the band 68to the loop 56. The opposite end of the steel band 68 is provided with aperpendicularly extending flange 70 arranged adjacent to the flange 67.

A bolt 71 adjustably connects the flanges 67, 70, as seen in Figure 2,to form the bands 65, 68 into a single unit when considered with the bar50. The bands 65, 68 are trained over the roller 63 and bear against thefriction material 64 so that the movement of the bands 65, 68 withrespect to' the bracket 60 will be retarded.

In knee structures for artificial legs as previously constructed, thetension of the joint increased as the bending increased so that sittingwithout releasing the tension on the knee became virtually impossible,and the wearer of the artificial leg became embarrassed- The actionofreleasing the tension on the springs of the conventional legstructures is in itself quite embarrassing to most persons and callsattention to the fact that an artificial limb is being worn.

In the instant invention, the tension of the springs holding the legstraight are greatest when the leg is straight, and least when the legis completely bent so that the act of sitting and rising is performednaturally without embarrassment to the wearer or the leg.

In the use and operation of the invention, the springs 54, 55 and 44have their tension adjusted by adjusting the bolts 51 and nut 31 so thatsufficient friction exists between the bands 65, 63 and the frictionmaterial 64 to hold the leg member 21 straight with respect to the legmember 22 under normal conditions. As the leg is bent during a sittingact the cushion 42 moves away from the cushion 38 allowing the mountingbolt 30, arm 46, and bar 50 to move upwardly so as to loosen the bands65, 68 which then slide across the friction material 64 and the roller63 and allows the bending about the pivots 23, 24v to take place.

As can be seen from the semi-diagrammatic figures, Figure 4 and Figure5, the bracket 60 moves about the pivot points 23,. 24 toward the bar 50so asto shorten the distance therebetween and relieve a portion of thetension on the springs-54, 55. Obviously the greater the degree ofbending of the upper leg member 22 with respect to the lower leg member21, the less tension which will be applied by the springs 54. i

Referring now to Figures 8 through 10, a modified form of the inventionis illustrated wherein the amputation of the natural limb has been madein, or slightly above the knee joint so that there is no upper legmember similar to the upper leg member 22 illustrated in the preferredform of the invention.

The modified form of the invention includes a V-joint stump 72 in aconventional manner using straps 73.

The socket member 22a is provided with a pair of hinge members 74, 75arranged on opposite sides thereof and secured by pivots 23a to theupper end of the lower leg member 21a. The pivots 23a, only one of whichis shown, are spaced apart laterally in aligned relation with their axesextending transversely of the leg member 210 in the same manner as thepivots 23, 24 in the preferred form of the invention.

A mounting plate 25a identical to the mounting bar 25 is mounted in thelower leg member 21a in the identical manner as the mounting of themounting bar 25. A mounting bolt 36a identical to the mounting boltcarries a bar 46a of the same construction as the arm 46. The head 36asecured to the upper end of the mounting bolt 39a is provided with aslot 76 extending centrally downwardly therethrough, for reasons to beassigned.

The upper end of the head 36a is provided with a :pair of cushion pads33a and 33b secured in horizontally aligned relation on opposite sidesof the slot 76. The socket member isprovided with a pair of cushion pads42a arranged to engage the cushion pads 38a, 38b when the stump 72 isaligned with the lower leg member 21a;

A plate a is resiliently mounted on the bar 46a by bolts 51a in the samemanner that the bar 50 is mounted on the arm 46. An arcuate bracket6tais arranged with. its concave surface upwardly and provided withrollers 63a adjacent the opposite ends of the lower face thereoft Thebracket 69a is integrally connected to the plate 50a by webs '77, 76extending between the respective opposite side edges thereof in themedial area thereof. The lower convex face of the bracket a is providedwith a friction band 6411 similar to the band 64 on the bracket 60.

A flexible steel band 65a is connected at 66a to the forward edge of thesocket member 22a and at 69a to the rear edge thereof. The band 65a maybe made in one piece, as illustrated in Figure 8, or in two pieces, asillustrated in the preferred form of the invention illustrated in Figure2. The band 65a extends beneath the bracket 60a in contact with thefriction member 64aand the roller 63a.

The action of the knee structure 20a is identical to the action of theknee structure 20 in that the tensions resisting bending thereof aregreatest when the knee is straight and leastwhen the knee is fully bent.

The band 65a slides on the bracket 60a and is retarded in its movementthereover by the friction material 64a. Tension on the plate 56amaintains the frictional relation between the band 65a and the frictionmaterial 64a. As the knee is bent to its fullest extent, the frictionalcontact is lessened sufficiently topermit easy movement of the kneejoint.

The band 65a, when the knee is straight, extends through the slot 76 inthe head 36a, as illustrated in Figure 9'.

While, in both the preferred form of the invention and spaced members,means extending transversely between said members pivotally securingsaid members together, flexible friction means extending between saidmembers for restraining the pivotal movement between said members, andspring biased means cooperatively engaging said flexible friction meansto vary the restraining 'e'tfect 5 of said flexible friction means, withsaid flexible friction means having its greatest restraining effect whensaid vertically spaced members are in aligned relation.

2. A device as claimed in claim 1 wherein the means extending betweensaid members includes a flexible band associated with said springbiasing means, and a friction bracket over which said band moves duringpivotal movement of said vertically spaced members.

3. A device as claimed in claim 2 wherein said bracket is positioned inthe upper of said vertically spaced members and said spring biasingmeans is positioned in the lower of said vertically spaced members.

6 4. A device as claimed in claim 2 wherein said bracket is positionedin said lower member and is carried by said spring biasing means.

References Cited in the file of this patent UNITED STATES PATENTS2,752,607 Bidwell July 3, 1956 FOREIGN PATENTS 382,563 Great BritainOct. 27, 1932

